Implementing Location Services in the Location-Transparent, Distributed Environment of the Internet
- Authors: Clayton, Peter G , Preston, Michael , Wells, George C
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430467 , vital:72693 , https://link.springer.com/book/10.1007/b13582?page=1#toc
- Description: This volume contains the papers presented at the 5th International Workshop on Advanced Parallel Processing Technologies, APPT 2003. This series of workshops is designed to strengthen the cooperation between the German and Chinese institutions active in the area of these technologies. It has continued to grow, providing an excellent forum for reporting advances in parallel processing technologies. The 5th workshop itself addressed the entire gamut of related topics, ranging from the architectural aspects of parallel computer hardware and system software to the applied technologies for novel applica-tions. For this workshop, we received over 191 full submissions from researchers all over the world. All the papers were peer-reviewed in depth and qualitatively graded on their relevance, originality, signi?cance, presentation, and the overall appropriateness for their acceptance. Any concerns raised were discussed in the program com-mittee. The organizing committee did an excellent job in selecting 78 papers (Among them, 21 were short ones) for presentation. In short, the papers included here represent the forefront of research from China, Germany, and the other countries.
- Full Text:
- Date Issued: 2003
Indomethacin reduces lipid peroxidation in rat brain homogenate by binding Fe2+
- Authors: Anoopkumar-Dukie, Shailendra , Lack, Barbara , McPhail, Kerry L , Nyokong, Tebello , Lambat, Zaynab , Maharaj, Deepat , Daya, Santy
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/304763 , vital:58487 , xlink:href="https://doi.org/10.1023/A:1021958016928"
- Description: One of the hallmarks of Alzheimer's disease (AD) is the progressive degeneration of cholinergic neurons in the cerebral cortex and hippocampus. It is generally accepted that this neuronal degeneration is due to free-radical-induced damage. These free radicals attack vital structural components of the neurons. This implies that agents that reduce free radical generation could potentially delay the progression of AD. Free radical generation in the brain is assisted by the presence of iron, required by the Fenton reaction. Thus, agents that reduce iron availability for this reaction could potentially reduce free radical formation. Since non steroidal anti-inflammatory drugs (NSAIDS) have been shown to reduce the severity of AD, we investigated the possible mechanism by which indomethacin could afford neuroprotection. Our results show that indomethacin (1 mM) is able to reduce the iron-induced rise in lipid peroxidation in rat brain homogenates. In addition, our NMR data indicate that indomethacin binds the Fe2+/Fe3+ ion. This was confirmed by a study using UV/Vis spectrophotometry. The results imply that indomethacin provides a neuroprotective effect by binding to iron and thus making it unavailable for free radical production.
- Full Text:
- Date Issued: 2003
Influence of cyclodextrins on the fluorescence, photostability and singlet oxygen quantum yields of zinc phthalocyanine and naphthalocyanine complexes
- Authors: Tau, Prudence , Ogunsipe, Abimbola O , Maree, Suzanne , Maree, M David , Nyokong, Tebello
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/304775 , vital:58488 , xlink:href="https://doi.org/10.1142/S1088424603000562"
- Description: The effects of formation of cyclodextrin inclusion complexes on the photochemical and photophysical properties of zinc phthalocyanine (ZnPc) and various peripherally substituted zinc phthalocyanines as well as zinc naphthalocyanine (ZnNPc) are investigated. The cyclodextrins employed were the hydroxypropyl-γ-cyclodextrin and unsubstituted β-cyclodextrin. Job's plots were employed to confirm the stoichiometry of the inclusion complexes and showed 2:1 and 4:1 (cyclodextrin:phthalocyanine) inclusion behavior. The phthalocyanine inclusion complexes showed larger singlet oxygen quantum yield (ϕΔ) values when compared to the free phthalocyanines before inclusion, for complexes 1 (zinc naphthalocyanine), 2 (zinc tetranitrophthalocyanine) and 4 (zinc tetra-tert-butylphenoxyphthalocyanine). The fluorescence quantum yields generally remained unchanged following inclusion.
- Full Text:
- Date Issued: 2003
Interrogate the information society:
- Authors: Berger, Guy
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159181 , vital:40275 , https://hdl.handle.net/10520/EJC146276
- Description: If there is one thing journalists should know about the "Information Society", it's this: never use the phrase as if its meaning speaks for itself. This is one of the most slippery and contentious phrases yet to grace contemporary discourse. For a start, why "Information Society" and not "Knowledge Society"? And why "society" and not "economy"? This is not academic semantics. There are wholly different meanings at stake with different implications for journalists, politicians, policy makers and many more.
- Full Text:
- Date Issued: 2003
Intervention in Bosnia-Herzegovina: lessons of peace‐maintenance for Africa?
- Authors: Bischoff, Paul, 1954-
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161365 , vital:40620 , DOI: 10.1080/10220460309545430
- Description: The Bosnian model is potentially a useful model for the development of a new strategic framework for African conflicts, particularly in situations where international organisations such as the United Nations are overstretched and regional organisations wish to take charge of peacebuilding operations.
- Full Text:
- Date Issued: 2003
Introduction [to the book "Scatter the Shrilling Bones" by Sithembele Isaac Xhegwana]
- Authors: Wright, Laurence
- Date: 2003
- Language: English
- Type: text , article
- Identifier: vital:7056 , http://hdl.handle.net/10962/d1007417
- Description: preprint , Scatter the Shrilling Bones by Sithembele Xhegwana comprises an ordered sequence of poems that conveys a journey both literal and spiritual. Revisitation is the organizing principle of the collection – the return to rural sources and origins by a consciousness estranged and illumined by modernity (cf. ‘The Return’). Underlying the collection is the theme of the night journey, whose archetype in western culture is Odysseus’ descent to the underworld – a pattern identified as such in the concluding essay ‘Starting from my Place: Notes on an Aesthetic’. The underworld here is literally the return to the home territory – a journey from Cape Town to the rural Eastern Cape – but also a revisiting of the mental world of traditional Africa: ‘Here at home, here all guilt begins’ (‘Homecoming’). The return journey is haunted by nightmare memories of mental illness, the schizophrenic episodes accompanying (or occasioned by?) the poet’s initial encounters with modernity. This illness is represented as both pathological and cultural – a price paid for challenging and rejecting the old certainties while grappling with new assumptions: “He undermines the ancestors, That’s why he suffers. Let him.” (‘To Himself’)
- Full Text:
- Date Issued: 2003
Pharmaceutical Pictograms: Part 1: Communicating Medicine Information to the Low-literate Patient
- Authors: Dowse, Roslind , Ehlers, Martina S
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/157026 , vital:40080
- Description: To assess the influence of formal education on the interpretation of pharmaceutical pictograms.
- Full Text:
- Date Issued: 2003
Pharmaceutical Pictograms: part 2: weird and wonderful interpretations
- Authors: Dowse, Roslind , Ehlers, Martina S
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/157037 , vital:40081
- Description: To assess the influence of formal education on the interpretation of pharmaceutical pictograms.
- Full Text:
- Date Issued: 2003
Photochemical studies of binuclear phenoxysubstituted phthalocyanines containing catecholate bridges
- Authors: Seotsanyana-Mokhosi, Itumeleng , Maree, Suzanne , Maree, M David , Nyokong, Tebello
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/304808 , vital:58492 , xlink:href="https://doi.org/10.1142/S1088424603000239"
- Description: Binuclear ZnPc complexes covalently bridged by catechol units have been synthesized and their absorption and photochemical properties examined. The complexes studied are 1,2-bis-2',9',16',23'-triphenoxyphthalocyaninatozinc benzene (6a), 1,2-bis-2'-9',16',23'-tri-4-carboxyphe-noxyphthalocyaninatozinc benzene (6b), 1,2-bis-2',9',16',23'-tri-4-nitrophenoxyphthalocyaninato- zinc benzene (6c) and 1,2-bis-2'-9',16',23'-tri-4-tert-butylphenoxyphthalocyaninatozinc benzene (6d). Larger intramolecular coupling was observed for 6b and 6c, containing the carboxyphenoxy and nitrophenoxy substituents, respectively, than for 6a and 6d. A single Q band peak was observed for the fluorescence spectra of 6b and 6c, whereas, 6a and 6d showed a split Q band. The absence of the high energy fluorescence peaks corresponding to absorbance peaks in the 640 nm region, suggests that the intramolecular coupling is broken by excitation for complexes 6b and 6c.
- Full Text:
- Date Issued: 2003
Phthalocyanines and related complexes as electrocatalysts for the detection of nitric oxide
- Authors: Nyokong, Tebello , Vilakazi, Sibulelo
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/290346 , vital:56741 , xlink:href="https://doi.org/10.1016/S0039-9140(03)00356-4"
- Description: Metallophthalocyanine (MPc) and metalloporphyrin complexes as well as some metalloproteins including myoglobin, hemoglobin, cyanocobalamin and cytochrome c catalyse the detection of nitric oxide (NO). The catalytic process often involve changes in the oxidation state of the catalyst. These complexes catalyse both the reduction and oxidation of NO. MPc complexes containing electroactive central metals such as CoPc and FePc generally show better catalytic activity towards the detection of NO than complexes containing electroinacive central metals. However, the involvement of ring based redox processes was confirmed for the homogenous NO catalysis using CoPc.
- Full Text:
- Date Issued: 2003
Pipes, poles and people:
- Authors: Kyazze, Sim
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159153 , vital:40273 , https://hdl.handle.net/10520/EJC146268
- Description: Tina James, a South African ICT consultant, tells the story of Minnie Barendse Kruger who had been struggling to get a Khoisan Cultural Village going in the Eastern Cape. Kruger set up a restaurant where traditional food is prepared, and the Barendse Griquas Trust stepped in and helped set up a multi-purpose Community Centre.
- Full Text:
- Date Issued: 2003
Press vs public enemy no 1:
- Authors: Berger, Guy
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159083 , vital:40266 , https://hdl.handle.net/10520/EJC146291
- Description: Our journalism about poverty is pitiful. It's a story about the poverty of our journalism. But let's start with the not-so-bad news: unlike many other countries, we do report poverty. Also, unlike many other places, we don't blame the victims - rather, we tend to be sympathetic.
- Full Text:
- Date Issued: 2003
Productivity and abundance of Sclerocarya birrea subsp. caffra in and around rural settlements and protected areas of the Bushbuckridge lowveld, South Africa
- Authors: Shackleton, Charlie M , Botha, Jenny , Emanuel, P L
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181607 , vital:43751 , xlink:href="https://doi.org/10.1080/14728028.2003.9752459"
- Description: Sclerocarya birrea (A. Rich.) Hochst, subsp. caffra (Sond.) Kokwaro is a common species throughout the semi-arid savannas of southern Africa, and is sought after by rural communities. It is frequently maintained in homesteads and fields in an agroforestry situation. It has also been identified by a number of international and national institutes as a key species for domestication and commercialisation. Yet, the sustainability of the resource and local user knowledge and practices have not been considered. This study reports on the abundance and productivity of S. birrea in four rural villages and neighbouring protected areas in the Bushbuckridge lowveld of the Limpopo Province, South Africa, where its common name is marula. The density of marula stems was measured in homestead plots, arable fields and the surrounding communal rangelands of each village. Fruit production was assessed by regular counting of fruit fall from marked trees of known size. Within the villages, fruit production was monitored via local community groups. Additional monitoring of fruiting was conducted on marked trees within local protected areas. The proportion of households planting or nurturing marula trees was determined through interviews with a stratified random sample of households. The density of marula trees was significantly higher in protected areas than the neighbouring communal lands, fields or homesteads. However, the majority of trees in protected areas were small, while those in homesteads were large and mature. Density of adult fruit-bearing female trees, was similar between the protected areas and homesteads, but less in fields and communal lands. S. birrea trees were maintained in 79 % of homesteads and 58 % of fields. Mean fruit yield per tree was significantly higher from village trees (less than 17 000 fruits) than protected area trees (more than 3 500 fruits), even after accounting for differences in tree size. The fresh mass of individual fruits was also greater on village trees than on trees in protected areas. Both these characteristics suggest some degree of historical selection of the trees in the homesteads and fields. There was a positive relationship between tree size and number of fruits produced.
- Full Text:
- Date Issued: 2003
Realistic autonomous fish for virtual reality
- Authors: Lobb, Adele , Bangay, Shaun D
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433398 , vital:72967 , https://doi.org/10.1145/602330.602361
- Description: We create realistic autonomous fish for Virtual Reality systems. The fish are realistic in appearance, movement and behaviour: the swimming behaviour being non-scripted, within real time rendering.The form of the fish is procedurally created. The size and shape of the form are controlled by a number of variables which are stored in a simple ASCII file. This allows efficient creation of different fish at run time.The behaviour is obtained by implementing a flocking algorithm.
- Full Text:
- Date Issued: 2003
Rendering optimisations for stylised sketching
- Authors: Winnemöller, Holger , Bangay, Shaun D
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/432922 , vital:72913 , https://doi.org/10.1145/602330.602353
- Description: We present work that specifically pertains to the rendering stage of stylised, non-photorealistic sketching. While a substantial body of work has been published on geometric optimisations, surface topologies, space-algorithms and natural media simulation, rendering-specific issues are rarely discussed in-depth even though they are often acknowledged. We investigate the most common stylised sketching approaches and identify possible rendering optimisations. In particular, we define uncertainty-functions, which are used to describe a human-error component, discuss how these pertain to geometric perturbation and textured silhouette sketching and explain how they can be cached to improve performance. Temporal coherence, which poses a problem for textured silhouette sketching, is addressed by means of an easily computed visibility-function. Lastly, we produce an effective yet surprisingly simple solution to seamless hatching, which commonly presents a large computational overhead, by using 3-D textures in a novel fashion. All our optimisations are cost-effective, easy to implement and work in conjunction with most existing algorithms.
- Full Text:
- Date Issued: 2003
Revised Schools and Sustainability Pack offers Curriculum Support
- Authors: Olvitt, Lausanne L
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/389852 , vital:68489 , xlink:href="https://eeasa.org.za/wp-content/uploads/2016/12/Bulletin_vol24-_March-2003.pdf"
- Description: Since the mid 1990s, the School Environmental Policy and Management Plan (SEP) Pack has supported educators in developing a whole-school environmental policy. This year, Share-Net has updated the pack in line with the South African revised National Curriculum and the National Environmental Education Programme (NEEP).
- Full Text:
- Date Issued: 2003
Self-Assembled Monolayers of Cobalt and Iron Phthalocyanine Complexes on Gold Electrodes
- Authors: Ozoemena, Kenneth I , Nyokong, Tebello , Westbroek, Philippe
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/290363 , vital:56743 , xlink:href="https://doi.org/10.1002/elan.200302753"
- Description: The self-assembling of the octa(hydroxyethylthio)-metallophthalocyanine {MOHETPc (M=Co and Fe)} complexes and their similar analogues, octabutylthiometallophthalocyanine {MOBTPc (M=Co and Fe)} complexes on gold electrodes are investigated. Comparative surface voltammetric insights into their distinct self-assembling properties with respect to the passivation of Faradaic processes and surface coverages, including their solution electrochemistry, suggest different orientations and non-cleavage of their CS bonds. In the pH 2−9 range, the reversible [M(III)Pc(−2)]+ / [M(II)Pc(−2)] redox couples show potential shifts close to −59 mV / pH. The gold electrodes modified with the SAMs of these species show electrocatalytic activity towards the oxidation of thiols (L-cysteine, homocysteine and penicillamine) and thiocyanate in acidic media with detection limits in the region of 10−7–10−6 mol dm−3. These monolayers are stable and easily reproducible.
- Full Text:
- Date Issued: 2003
Simulation and visualization of fire using extended Lindenmayer systems
- Authors: Zaniewski, Tomasz , Bangay, Shaun D
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433303 , vital:72960 , https://doi.org/10.1145/602330.602337
- Description: This research introduces a method of using Lindenmayer Systems to model the spreading and behavior of fire inside a factory building. The research investigates the use of L-System propagated fires for determining factors such as where the fire is most likely to spread first and how fast. It also looks at an alternative way of storing the Lindenmayer System, not in the form of a string but rather as a graph. A variation on the building and traversal process is also investigated, in which the L-System is traversed depth first instead of breadth first. Results of fire propagation are presented and we conclude that L-Systems are a suitable tool for fire propagation.
- Full Text:
- Date Issued: 2003
Synthesis, spectral and electrochemical properties of a new family of pyrrole substituted cobalt, iron, manganese, nickel and zinc phthalocyanine complexes
- Authors: Obirai, Joe , Rodrigues, Nazaré Pereira , Bedioui, Fethi , Nyokong, Tebello
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/304852 , vital:58496 , xlink:href="https://0-doi.org.wam.seals.ac.za/10.1142/S1088424603000641"
- Description: A new family of pyrrole substituted metallophthalocyanine complexes, namely cobalt(II), iron(II), manganese(III), nickel(II) and zinc(II) tetrakis-4-(pyrrol-1-yl)phenoxy phthalocyanines (noted as M(TPhPyrPc), where M is the metallic cation) have been synthesized and fully characterized. In particular, the UV-visible spectra of the iron and nickel complexes showed extensive aggregation even at low concentrations. The cyclic voltammetry of the cobalt, iron and manganese complexes showed three to four redox couples assigned to metal and ring based processes. Spectroelectrochemistry of the manganese derivative confirmed that the synthesized complex is MnIII(TPhPyrPc-2) and that the reduction of MnII(TPhPyrPc-2) to be centred on the ring and rather than on the metal, forming the MnII(TPhPyrPc-4) species. Also, the electrochemical polymerization of these newly synthesized pyrrole-substituted phthalocyanines has been demonstrated in the case of the cobalt complex and the electrocatalytic activity of the obtained film has been tested towards the oxidation of L-cysteine.
- Full Text:
- Date Issued: 2003
Synthesis, spectroscopy and photochemistry of octasubstituted thiol-derivatized phthalocyaninatozinc (II) complexes
- Authors: Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/290401 , vital:56746 , xlink:href="https://doi.org/10.1016/S1387-7003(03)00218-1"
- Description: Synthesis, spectroscopic and photochemical characterization of phenylthiol-derivatized zinc phthalocyanine complex: 2,3,9,10,16,17,23,24-octa(4-methylphenylthio-)phthalocyaninatozinc(II) [ZnPc(SC6H4CH3)8] (3a) and its alkanethiol derivative, 2,3,9,10,16,17,23,24-octabutylthiophthalocyaninatozinc(II) [ZnPc(SC4H9)8] (3b) are described. Spectroscopic analyses show that 3a has a higher aggregation tendency than 3b in organic solvents. Photochemical studies indicate that 3b is more photostable and more efficient at singlet oxygen generation than 3a.
- Full Text:
- Date Issued: 2003